1. Field of the Invention
The present invention relates to a method of manufacturing a display unit using an organic light emitting device or liquid crystal and a display unit.
2. Description of the Related Art
In recent years, in the field of display units, next-generation displays have been actively developed, and space saving, high luminance, low power consumption and the like have been requested. As such a display unit, an organic EL (Electro Luminescence) display unit using an organic light emitting device has attracted attention. The organic EL display unit has characteristics as follows. That is, since the organic EL display unit is self-light emitting type, the view angle is wide. Since the organic EL display unit does not need a backlight, electric power saving is able to be expected, its response is high, and the thickness of the unit itself is able to be decreased. Further, since a plastic substrate is used as a substrate of the organic EL display unit in order to use the inherent flexibility of an organic light emitting material, the organic EL display unit attracts attention as a unit having flexibility.
Of the drive systems in the organic EL display unit, active matrix system in which a thin film transistor (TFT) as a drive element is used has more superior response and superior resolution to those of passive matrix system. Thus, the active matrix system is regarded as a drive system particularly suitable for the organic EL display unit having the foregoing advantages.
The active matrix organic EL display unit has a drive panel provided with an organic light emitting device (organic EL device) including a light emitting layer made of an organic light emitting material between a first electrode and a second electrode, and the drive element (thin film transistor) for driving the organic light emitting device. The drive panel and a sealing panel are bonded with an adhesive layer in between so that the organic light emitting device is sandwiched therebetween.
In the organic EL display unit, there are bottom emission type in which light from each organic light emitting device is emitted to the foregoing drive panel side and top emission type in which such light is emitted to the foregoing sealing panel side on the contrary. The latter type is able to increase the aperture ratio more, and the latter type is the developmental mainstream.
In the top emission type organic EL display unit, for the first electrode on the lower layer side, that is, on the drive element side, a material having relatively large work function with which hole is easily injected into the light emitting layer, for example, an oxide conductive material such as ITO (Indium Tin Oxide) is used. However, the oxide conductive material has resistivity higher by double or triple digit than that of a general wiring metal material or the like, and thus the oxide conductive material has not been able to be utilized to a material of wirings and the like other than the first electrode. Further, there has been a disadvantage that light emitted in a downward direction may not be effectively used.
Therefore, for example, Japanese Unexamined Patent Application Publication No. 2003-115393 discloses that a metal film having high reflectance and low resistivity is formed as a layer located lower than a transparent conducting film such as ITO, and thereby being utilized to wirings and the like.